Remove remaining references to @PreventSpuriousRebuilds.

Change-Id: Icc8bff0734bfa5decc3c9db548c4104f34057e95
diff --git a/dev/core/src/com/google/gwt/util/tools/package-info.java b/dev/core/src/com/google/gwt/util/tools/package-info.java
index 5ed4048..ce57d71 100644
--- a/dev/core/src/com/google/gwt/util/tools/package-info.java
+++ b/dev/core/src/com/google/gwt/util/tools/package-info.java
@@ -17,5 +17,4 @@
 /**
  * Utility classes for building GWT command-line applications.
  */
-@com.google.gwt.util.PreventSpuriousRebuilds
 package com.google.gwt.util.tools;
diff --git a/dev/core/src/com/google/gwt/util/tools/shared/package-info.java b/dev/core/src/com/google/gwt/util/tools/shared/package-info.java
index 83bd5cd..7820eeb 100644
--- a/dev/core/src/com/google/gwt/util/tools/shared/package-info.java
+++ b/dev/core/src/com/google/gwt/util/tools/shared/package-info.java
@@ -17,5 +17,4 @@
 /**
  * Utility classes shared between gwt-dev and gwt-servlet.
  */
-@com.google.gwt.util.PreventSpuriousRebuilds
 package com.google.gwt.util.tools.shared;